1. Field of the Invention
The present invention relates to an apparatus and method for supplying, mixing and applying 5-aminolevulinic acid, also known as 5-amino-4-oxo-pentanoic acid (hereinafter referred to as ALA), in a simple, cost effective manner. More particularly, the present invention relates to a method and apparatus for supplying a two component system comprising ALA and a liquid diluent, wherein the two components are inhibited from contact with each other, as well as contact with light, moisture and air, until just prior to use, when they are mixed. Topically applied ALA, in association with irradiation with light, has been clinically tested in the treatment of pre-cancerous lesions such as actinic keratosis.
2. Description of Related Art
It is known that ALA is degraded in aqueous solution. The inventor has further found that ALA turns brown, and presumably is degraded, in all sorts of topical vehicles such as creams, ointments and solid vehicles. Thus the inventor found it necessary to employ a means to store ALA until ready for treatment in topical applications, as well as to mix the ALA just prior to use, and to focus the area of application to the skin.
In the field of dentistry, U.S. Pat. No. 5,171,149 to Alpert discloses the use of crushable glass ampules for the application of at least one dentin conditioner onto teeth. Glass ampules are provided in a tube with an open applicator at one end. The ampules are crushed to allow the tube contents to flow out of the applicator to prepare the dentin surface of teeth for bonding.
U.S. Pat. No. 5,490,736 to Haber et al. (hereinafter referred to as Haber) discloses a topical applicator having a barrier interposed between a dry medication and a diluent. The barrier, which partitions an applicator body shared in common by the medication and diluent, is ruptured or displaced by pressure on the applicator body. Haber discloses several means for exposing a medicine saturated swab within the applicator body for topical treatment of acne.
Although it is known that ALA degrades in moisture, the present inventor knows of no prior art methods of storing, mixing and applying ALA via a single device which prevents degradation by moisture, other than storage of the ALA in an anhydrous environment.